In a mammal, a tooth is comprised of an inner dentin layer and a protective outer hard enamel layer. The enamel layer of a tooth is naturally an opaque white or slightly off-white color; the enamel layer, however, may become stained or discolored. The enamel layer of a tooth is composed of hydroxyapatite mineral crystals that create a somewhat porous surface. It is believed that the porous nature of the enamel allows staining agents and discoloring substances to permeate the enamel layer and occupy the microscopic spaces and eventually alter the color of the tooth.
Consumers wishing to alter the color of their teeth have a limited variety of products from which to choose. Successful application of some color altering products, such as veneers, crowns, and caps, involves destruction of tooth enamel, and requires the services of a dental professional. Alternatively, a variety of less destructive oral care formulations are known in the art which may be applied to the surface of a tooth and purport to alter the color of the tooth enamel.
Use of a permanent coloring coat for teeth by application of dry powdered colored particles to a layer of glue applied to the buccal surface of the teeth is known in the art. Other conventional means of addressing tooth discoloration include whitening teeth by application of a liquid dental composition containing a peroxide whitening constituent dispersed in an aqueous liquid vehicle and a film forming component or applying metallic oxides simultaneously having film-forming and pigmenting properties simulate the approximate color of natural.